set_intersection (InputIterator1 first1, InputIterator1 last1,
           InputIterator2 first2, InputIterator2 last2,
           OutputIterator result);

// C++中使用STL查找两个向量之间的公共元素
  
#include <bits/stdc++.h>
using namespace std;
  
int main()
{
  
    // 获取向量
    vector<int> vector1 = {1, 45, 54, 71, 76, 12};
    vector<int> vector2 = {1, 7, 5, 4, 6, 12};
  
    // 将向量排序
    sort(vector1.begin(), vector1.end());
    sort(vector2.begin(), vector2.end());
  
    // 输出向量
    cout << "First Vector: ";
    for (int i = 0; i < vector1.size(); i++)
        cout << vector1[i] << " ";
    cout << endl;
  
    cout << "Second Vector: ";
    for (int i = 0; i < vector2.size(); i++)
        cout << vector2[i] << " ";
    cout << endl;
  
    // 初始化一个向量，用于存储公共值以及迭代器用于遍历该向量
    vector<int> v(vector1.size() + vector2.size());
    vector<int>::iterator it, st;
  
    it = set_intersection(vector1.begin(),
                          vector1.end(),
                          vector2.begin(),
                          vector2.end(),
                          v.begin());
  
    cout << "\nCommon elements:\n";
    for (st = v.begin(); st != it; ++st)
        cout << *st << ", ";
    cout << '\n';
  
    return 0;
}

First Vector: 1 12 45 54 71 76 
Second Vector: 1 4 5 6 7 12 

公共元素：
1, 12,